The leaders of France and Germany today issued a stark warning to Washington and the global financial community that Europe would lead the way in restructuring the global financial system and ushering in a more "moral" form of capitalism.

Appearing to set aside recent disagreements over how to handle the economic downturn, Nicolas Sarkozy, the French president, and Angela Merkel, Germany's chancellor, presented a united front in their efforts to reform a system they said had led to "unprecedented instabilities".

The entente came on a day that Germany took a 25% stake plus one share in Commerzbank in return for an additional €10bn (£9bn) capital injection into the bank.

Both leaders stressed the need for Europe to play a significant role at the summit of G20 nations in London in April, when the group of leading and emerging countries will hammer out ways of reinforcing the architecture of global regulation.

Twelve days before the inauguration of Barack Obama as US president, Sarkozy gave a characteristically frank verdict on the role of the US in future negotiations. "Let's be clear: in the 21st century it is no longer a single nation who can say what we must do, what we must think," he said, adding that Britain's place in the economic discussions was with her European allies "and not just with the US".

Speaking at a conference in Paris on the future of capitalism, the leaders of the EU's powerhouse member states agreed on the need to make long-term changes to the old financial order, which Sarkozy said had been "perverted" by an "amoral" form of unbridled finance capitalism. Hailing the "return of the state", the right-wing market liberal said he hoped a more responsible model of global finance would emerge from the wreckage of the current crisis. Merkel, also a centre-right conservative, said she would "react very strongly" if attempts were made to block tighter regulation.

"Once everything is going better, the financial markets will tell us, you politicians don't need to get involved because everything is working again," she said. "I will stay firm, we must not repeat the mistakes of the past."

Calling for the creation of a new economic council to run along the lines of the UN Security Council, the chancellor said she was also in favour of a sustainable economy "world charter" which would set out new rules for long-term financial management. "No country can act alone in this day and age, not even the United States, however powerful they may be," she said.

Former prime minister Tony Blair, also speaking at the conference, agreed it was "utterly crucial" for far-reaching reforms to be carried out to recover from the recent "economic tsunami". "We have mid-20th-century international institutions governing a 21st century world ... The reform of the IMF, the World Bank, the financial regulatory system [is] long overdue," he said.